Year-end Sale % OFF 
Abstract
The adverse effects of D-tryptophan and the possibility of it being a surrogate index for predicting adverse effects in rats were investigated. Male rats were fed one of several test diets (20% casein diets with 0% (control), 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% D-tryptophan) for 21 d, and 24-h urine samples on the final day of the experiment were collected. Analyses of food intake and body-weight changes revealed adverse effects to be observed in the group fed the 0.3% D-tryptophan diet. We propose urinary levels of 3-hydroxykynurenine/3-hydroxyanthranilic acid to be surrogate indicators for predicting the adverse effects of D-tryptophan from the break point of body-weight gains and urinary levels of D-tryptophan metabolites. The reaction 3-hydroxykynurenine→3-hydroxyanthranilic acid is catalyzed by the pyridoxal phosphate-dependent enzyme kynureninase. Increasing urinary 3-hydrokykynurenine indicates kynureninase deficiency. Intake of D-tryptophan in rats fed the 0.3% D-tryptophan diet was 0.21 g/kg body weight and feeding of the 0.3% D-tryptophan diet did not elicit adverse effects. Thus, the safe level of D-tryptophan was less than 0.2% in the diet, 0.15 g/kg body weight, in rats.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
